Multi-function button touch circuit

Abstract

The utility model discloses a multifunctional key touch circuit, including an NFC module, a main control module and a touch screen interface module. The NFC module includes an RFID card reader chip U101 and a first microcontroller chip U103, wherein the 24th terminal of the RFID card reader chip U101 is electrically connected to the 1st terminal of the first microcontroller chip U103, and the 6th terminal of the RFID card reader chip U101 is electrically connected to the 14th terminal of the first microcontroller chip U103. The multifunctional key touch circuit disclosed by the utility model has the beneficial effect that a circuit structure of the key touch circuit is disclosed in detail, and multiple functions such as touch screen input and key input can be realized based on the electrical connection combination between the circuits such as the NFC module, the main control module and the touch screen interface module.

Description

Technical Field

[0001] The utility model belongs to the field of key touch control, and in particular relates to a multifunctional key touch control circuit. Background Art

[0002] The invention patent application with publication number CN111309239A and subject name is A touch control system for realizing multiple screens. Its IPC classification number is G06F3 / 0488, and its technical solution discloses that "the touch control system for realizing multiple screens is used to control the working state of a touch panel. As a prior art, the touch panel should at least include a display screen module 10, an LED lamp 20, and a vibration motor (not shown). The display screen module 10 is used to present the screen to be displayed according to the display information, and it should include a display panel, a signal processing module, etc. It is a prior art and will not be repeated here. The LED lamp 20 and the vibration motor are usually used to give prompts or feedback when the user inputs an instruction to reveal that the touch input is valid. At the same time, when the user inputs an incorrect instruction, the light flashes or vibrates to prompt the user to re-enter the instruction."

[0003] See CN111309239A Figure 2 The above invention patent application has disclosed a mechanical structure of a touch control system with a key touch function. However, the technical solution disclosed in the above invention patent application does not further disclose the circuit structure of a multi-function key touch circuit, which needs to be further improved. Utility Model Content

[0004] The utility model aims at the prior art, overcomes the above defects and provides a multifunctional key touch circuit.

[0005] The utility model adopts the following technical scheme, a multifunctional key touch circuit, including an NFC module, a main control module and a touch screen interface module, wherein:

[0006] The NFC module includes an RFID card reader chip U101 and a first microcontroller chip U103. Terminal 24 of the RFID card reader chip U101 is electrically connected to terminal 1 of the first microcontroller chip U103. Terminal 6 of the RFID card reader chip U101 is electrically connected to terminal 14 of the first microcontroller chip U103.

[0007] The main control module includes a second microcontroller chip U5, the USB expansion module includes a USB hub controller U4, the touch screen interface module includes a common mode choke U6, and the touch screen interface module also includes a button SWITCH1, a button SWITCH2, a button SWITCH3, a button SWITCH4 and a button SWITCH5, wherein:

[0008] Terminal 2 of the common mode choke coil U6 is electrically connected to terminal 10 of the USB hub controller U4; terminal 3 of the common mode choke coil U6 is electrically connected to terminal 11 of the USB hub controller U4;

[0009] The common end between terminals 2 and 4 of button SWITCH1 is connected to terminal 18 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH2 is connected to terminal 19 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH3 is connected to terminal 20 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH4 is connected to terminal 21 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH5 is connected to terminal 22 of the second microcontroller chip U5.

[0010] As a further preferred technical solution of the above technical solution, the multi-function key touch circuit also includes a USB expansion module, an upgrade interface module, a serial port to USB module, and an NFC interface module. The USB expansion module includes a USB interface J2, the upgrade interface module includes a USB interface J3, the serial port to USB module includes a USB conversion chip U3, and the NFC interface module includes an NFC interface J5, wherein:

[0011] Terminal 34 of the second microcontroller chip U5 is electrically connected to terminal 4 of the USB interface J2, and terminal 34 of the second microcontroller chip U5 is electrically connected to terminal 5 of the USB interface J3 via a current limiting resistor R78;

[0012] Terminal 31 of the second microcontroller chip U5 is electrically connected to terminal 7 of the USB interface J2, and terminal 31 of the second microcontroller chip U5 is electrically connected to terminal 3 of the USB interface J3 via a current limiting resistor R74;

[0013] Terminal 30 of the second microcontroller chip U5 is electrically connected to terminal 5 of the USB interface J2, and terminal 30 of the second microcontroller chip U5 is electrically connected to terminal 1 of the USB interface J3 via a current limiting resistor R52;

[0014] The terminal 10 of the second microcontroller chip U5 is electrically connected to the terminal 5 of the USB conversion chip U3;

[0015] The terminal 11 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the USB conversion chip U3;

[0016] Terminal 12 of the second microcontroller chip U5 is electrically connected to terminal 1 of the NFC interface J5 via a current limiting resistor R86;

[0017] Terminal 13 of the second microcontroller chip U5 is electrically connected to terminal 2 of the NFC interface J5 via a current limiting resistor R83.

[0018] As a further preferred technical solution of the above technical solution, the multi-function key touch circuit also includes an identity recognition module and a current detection module, the identity recognition module includes a transient suppression diode D87 and a transient suppression diode D88, the identity recognition module also includes a resistor R129 and a resistor R132, and the current detection module includes a current detection amplifier chip U7 and a current detection amplifier chip U8, wherein:

[0019] The terminal 16 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the current detection amplifier chip U7 through the resistor R129, and the common terminal between the resistor R129 and the terminal 1 of the current detection amplifier chip U7 is connected to the transient suppression diode D87;

[0020] Terminal 17 of the second microcontroller chip U5 is electrically connected to terminal 1 of the current detection amplifier chip U8 through resistor R132, and a common terminal between the resistor R132 and terminal 1 of the current detection amplifier chip U8 is connected to a transient suppression diode D88.

[0021] As a further preferred technical solution of the above technical solution, the multi-function key touch circuit also includes a vibration motor module, the vibration motor module includes a vibration motor MOTOR1 and a contact connector J7, and the vibration motor module also includes a vibration motor MOTOR2 and a contact connector J6, wherein:

[0022] Terminal 1 of the vibration motor MOTOR1 is electrically connected to terminal 1 of the contact connector J7, terminal 2 of the vibration motor MOTOR1 is electrically connected to terminal 4 of the contact connector J7, and the common terminal between terminal 1 of the contact connector J7 and terminal 2 of the contact connector J7 is connected to the common terminal between terminal 3 of the current detection amplifier chip U7 and terminal 4 of the current detection amplifier chip U7;

[0023] Terminal 1 of the vibration motor MOTOR2 is electrically connected to terminal 1 of the contact connector J6, terminal 2 of the vibration motor MOTOR2 is electrically connected to terminal 4 of the contact connector J6, and the common terminal between terminal 1 of the contact connector J6 and terminal 2 of the contact connector J6 is connected to the common terminal between terminal 3 of the current detection amplifier chip U8 and terminal 4 of the current detection amplifier chip U8.

[0024] As a further preferred technical solution of the above technical solution, the vibration motor module further includes an N-channel enhancement type MOSFET tube Q2 and a small signal switch diode D2, and the vibration motor module further includes an N-channel enhancement type MOSFET tube Q1 and a small signal switch diode D3, wherein:

[0025] The common end between terminal 1 of contact connector J7 and terminal 2 of contact connector J7 is connected to the cathode of small signal switch diode D2, the common end between terminal 3 of contact connector J7 and terminal 4 of contact connector J7 is connected to the common end between the anode of small signal switch diode D2 and the drain of N-channel enhancement type MOSFET Q2, and the gate of N-channel enhancement type MOSFET is connected to terminal 39 of the second microcontroller chip U5 through resistor R18;

[0026] The common end between terminal 1 of contact connector J6 and terminal 2 of contact connector J6 is connected to the cathode of small signal switch diode D3, the common end between terminal 3 of contact connector J6 and terminal 4 of contact connector J6 is connected to the common end between the anode of small signal switch diode D3 and the drain of N-channel enhancement MOSFET Q2, and the gate of N-channel enhancement MOSFET is connected to terminal 40 of the second microcontroller chip U5 through resistor R18.

[0027] The multifunctional key touch circuit disclosed by the utility model has the beneficial effect that a circuit structure of the key touch circuit is disclosed in detail, and multiple functions such as touch screen input and key input can be realized based on the electrical connection combination between circuits such as the NFC module, the main control module and the touch screen interface module. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a circuit schematic diagram of the NFC module of this application.

[0029] Figure 2 It is a circuit schematic diagram of the backlight module of the present application.

[0030] Figure 3 It is a circuit schematic diagram of the main control module of this application.

[0031] Figure 4 It is a circuit schematic diagram of the NFC interface module of the present application.

[0032] Figure 5 It is a circuit schematic diagram of the vibration motor module of the present application.

[0033] Figure 6 It is a circuit schematic diagram of the current detection module of the present application.

[0034] Figure 7 It is a circuit schematic diagram of the identity recognition module of this application.

[0035] Figure 8 It is a circuit schematic diagram of the USB expansion module of the present application.

[0036] Fig. 9 It is a circuit schematic diagram of the upgrade interface module of the present application.

[0037] Fig.10 It is a circuit schematic diagram of the external interface module of the present application.

[0038] Fig.11 It is a circuit schematic diagram of the serial port to USB module of the present application.

[0039] Fig.12 It is a circuit schematic diagram of the touch screen interface module of the present application.

[0040] Fig.13 It is a circuit schematic diagram of the peripheral circuit of this application. DETAILED DESCRIPTION

[0041] The utility model discloses a multifunctional key touch circuit. Figure 1-13 , the specific implementation methods of the utility model are further described.

[0042] Example 1.

[0043] Preferably, the multifunctional key touch circuit includes an NFC module, a main control module and a touch screen interface module, wherein:

[0044] The NFC module includes an RFID card reader chip U101 and a first microcontroller chip U103. Terminal 24 of the RFID card reader chip U101 is electrically connected to terminal 1 of the first microcontroller chip U103. Terminal 6 of the RFID card reader chip U101 is electrically connected to terminal 14 of the first microcontroller chip U103.

[0045] The main control module includes a second microcontroller chip U5, the USB expansion module includes a USB hub controller U4, the touch screen interface module includes a common mode choke U6, and the touch screen interface module also includes a button SWITCH1, a button SWITCH2, a button SWITCH3, a button SWITCH4 and a button SWITCH5, wherein:

[0046] Terminal 2 of the common mode choke coil U6 is electrically connected to terminal 10 of the USB hub controller U4; terminal 3 of the common mode choke coil U6 is electrically connected to terminal 11 of the USB hub controller U4;

[0047] The common end between terminals 2 and 4 of button SWITCH1 is connected to terminal 18 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH2 is connected to terminal 19 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH3 is connected to terminal 20 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH4 is connected to terminal 21 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH5 is connected to terminal 22 of the second microcontroller chip U5.

[0048] The multi-function key touch circuit further includes a USB expansion module, an upgrade interface module, a serial port to USB module, and an NFC interface module. The USB expansion module includes a USB interface J2, the upgrade interface module includes a USB interface J3, the serial port to USB module includes a USB conversion chip U3, and the NFC interface module includes an NFC interface J5.

[0049] Terminal 34 of the second microcontroller chip U5 is electrically connected to terminal 4 of the USB interface J2, and terminal 34 of the second microcontroller chip U5 is electrically connected to terminal 5 of the USB interface J3 via a current limiting resistor R78;

[0050] Terminal 31 of the second microcontroller chip U5 is electrically connected to terminal 7 of the USB interface J2, and terminal 31 of the second microcontroller chip U5 is electrically connected to terminal 3 of the USB interface J3 via a current limiting resistor R74;

[0051] Terminal 30 of the second microcontroller chip U5 is electrically connected to terminal 5 of the USB interface J2, and terminal 30 of the second microcontroller chip U5 is electrically connected to terminal 1 of the USB interface J3 via a current limiting resistor R52;

[0052] The terminal 10 of the second microcontroller chip U5 is electrically connected to the terminal 5 of the USB conversion chip U3;

[0053] The terminal 11 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the USB conversion chip U3;

[0054] Terminal 12 of the second microcontroller chip U5 is electrically connected to terminal 1 of the NFC interface J5 via a current limiting resistor R86;

[0055] Terminal 13 of the second microcontroller chip U5 is electrically connected to terminal 2 of the NFC interface J5 via a current limiting resistor R83.

[0056] The multifunctional key touch circuit further includes an identity recognition module and a current detection module. The identity recognition module includes a transient suppression diode D87 and a transient suppression diode D88. The identity recognition module also includes a resistor R129 and a resistor R132. The current detection module includes a current detection amplifier chip U7 and a current detection amplifier chip U8.

[0057] The terminal 16 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the current detection amplifier chip U7 through the resistor R129, and the common terminal between the resistor R129 and the terminal 1 of the current detection amplifier chip U7 is connected to the transient suppression diode D87;

[0058] Terminal 17 of the second microcontroller chip U5 is electrically connected to terminal 1 of the current detection amplifier chip U8 through resistor R132, and a common terminal between the resistor R132 and terminal 1 of the current detection amplifier chip U8 is connected to a transient suppression diode D88.

[0059] The multi-function button touch circuit further includes a vibration motor module, the vibration motor module includes a vibration motor MOTOR1 and a contact connector J7, and the vibration motor module further includes a vibration motor MOTOR2 and a contact connector J6, wherein:

[0060] Terminal 1 of the vibration motor MOTOR1 is electrically connected to terminal 1 of the contact connector J7, terminal 2 of the vibration motor MOTOR1 is electrically connected to terminal 4 of the contact connector J7, and the common terminal between terminal 1 of the contact connector J7 and terminal 2 of the contact connector J7 is connected to the common terminal between terminal 3 of the current detection amplifier chip U7 and terminal 4 of the current detection amplifier chip U7;

[0061] Terminal 1 of the vibration motor MOTOR2 is electrically connected to terminal 1 of the contact connector J6, terminal 2 of the vibration motor MOTOR2 is electrically connected to terminal 4 of the contact connector J6, and the common terminal between terminal 1 of the contact connector J6 and terminal 2 of the contact connector J6 is connected to the common terminal between terminal 3 of the current detection amplifier chip U8 and terminal 4 of the current detection amplifier chip U8;

[0062] The vibration motor module further includes an N-channel enhancement type MOSFET tube Q2 and a small signal switch diode D2, and the vibration motor module further includes an N-channel enhancement type MOSFET tube Q1 and a small signal switch diode D3, wherein:

[0063] The common end between terminal 1 of contact connector J7 and terminal 2 of contact connector J7 is connected to the cathode of small signal switch diode D2, the common end between terminal 3 of contact connector J7 and terminal 4 of contact connector J7 is connected to the common end between the anode of small signal switch diode D2 and the drain of N-channel enhancement type MOSFET Q2, and the gate of N-channel enhancement type MOSFET is connected to terminal 39 of the second microcontroller chip U5 through resistor R18;

[0064] The common end between terminal 1 of contact connector J6 and terminal 2 of contact connector J6 is connected to the cathode of small signal switch diode D3, the common end between terminal 3 of contact connector J6 and terminal 4 of contact connector J6 is connected to the common end between the anode of small signal switch diode D3 and the drain of N-channel enhancement MOSFET Q2, and the gate of N-channel enhancement MOSFET is connected to terminal 40 of the second microcontroller chip U5 through resistor R18.

[0065] The NFC module further includes a voltage stabilizing chip U102 , and a capacitor C5 is connected in parallel between terminal 1 and terminal 3 of the voltage stabilizing chip U102 .

[0066] Among them, the multi-function button touch circuit also includes a backlight module, an external interface module, a peripheral circuit and other circuits.

[0067] The RFID card reader chip U101 preferably adopts MFRC522.

[0068] Among them, the voltage regulator chip U102 preferably adopts FS8844-33GC.

[0069] Among them, the first microcontroller chip U103 preferably adopts STC8G1K17.

[0070] Among them, the second microcontroller chip U5 preferably adopts STM32F072C8T6.

[0071] Among them, the USB interface J3 preferably adopts USB-1750-L1G.

[0072] The USB conversion chip U3 preferably adopts FT232RL-REL.

[0073] Among them, the transient suppression diode D87 is preferably LXES15AAA1-153.

[0074] Among them, the transient suppression diode D88 is preferably LXES15AAA1-153.

[0075] Among them, the current detection amplifier chip U7 preferably adopts IC_INA180A4.

[0076] Among them, the current detection amplifier chip U8 preferably adopts IC_INA180A4.

[0077] Among them, the common mode choke U6 is preferably CM0805C221R-10.

[0078] Among them, the USB hub controller U4 preferably adopts FE1.1S.

[0079] Among them, the contact connector J7 preferably adopts 1.5MM_4P.

[0080] Among them, the contact connector J6 preferably adopts 1.5MM_4P.

[0081] Among them, the small signal switching diode D2 is preferably LL4148.

[0082] Among them, the small signal switching diode D3 is preferably LL4148.

[0083] Among them, the N-channel enhancement type MOSFET Q2 preferably adopts AO3414.

[0084] Among them, the N-channel enhancement type MOSFET Q1 preferably adopts AO3414.

[0085] Therefore, the multifunctional key touch circuit disclosed in this embodiment discloses in detail a circuit structure of the key touch circuit, which can realize multiple functions such as touch screen input and key input based on the electrical connection combination between circuits such as the NFC module, the main control module and the touch screen interface module.

[0086] Example 2.

[0087] Embodiment 2 is based on embodiment 1, and as an extension, the storage area of ​​the second microcontroller chip U5 of the main control module can be written through the NFC module and the NFC interface module. As an example, the information written to the storage area of ​​the second microcontroller chip U5 of the main control module can be a website.

[0088] It is worth mentioning that the technical features such as the specific selection of the vibration motor MOTOR1 involved in this utility model patent application should be regarded as the prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional methods in the field, and should not be regarded as the inventive point of this utility model patent. This utility model patent will not be further elaborated.

[0089] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A multifunctional key touch circuit, characterized in that: It includes NFC module, main control module and touch screen interface module, among which: The NFC module includes an RFID card reader chip U101 and a first microcontroller chip U103. Terminal 24 of the RFID card reader chip U101 is electrically connected to terminal 1 of the first microcontroller chip U103. Terminal 6 of the RFID card reader chip U101 is electrically connected to terminal 14 of the first microcontroller chip U103. The main control module includes a second microcontroller chip U5, the USB expansion module includes a USB hub controller U4, the touch screen interface module includes a common mode choke U6, and the touch screen interface module also includes a button SWITCH1, a button SWITCH2, a button SWITCH3, a button SWITCH4 and a button SWITCH5, wherein: Terminal 2 of the common mode choke coil U6 is electrically connected to terminal 10 of the USB hub controller U4; terminal 3 of the common mode choke coil U6 is electrically connected to terminal 11 of the USB hub controller U4; The common end between terminals 2 and 4 of button SWITCH1 is connected to terminal 18 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH2 is connected to terminal 19 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH3 is connected to terminal 20 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH4 is connected to terminal 21 of the second microcontroller chip U5; the common end between terminals 2 and 4 of button SWITCH5 is connected to terminal 22 of the second microcontroller chip U5.

2. The multifunctional key touch circuit according to claim 1, characterized in that: The multi-function key touch circuit also includes a USB expansion module, an upgrade interface module, a serial port to USB module, and an NFC interface module. The USB expansion module includes a USB interface J2, the upgrade interface module includes a USB interface J3, the serial port to USB module includes a USB conversion chip U3, and the NFC interface module includes an NFC interface J5, wherein: Terminal 34 of the second microcontroller chip U5 is electrically connected to terminal 4 of the USB interface J2, and terminal 34 of the second microcontroller chip U5 is electrically connected to terminal 5 of the USB interface J3 via a current limiting resistor R78; Terminal 31 of the second microcontroller chip U5 is electrically connected to terminal 7 of the USB interface J2, and terminal 31 of the second microcontroller chip U5 is electrically connected to terminal 3 of the USB interface J3 via a current limiting resistor R74; The terminal 30 of the second microcontroller chip U5 is electrically connected to the terminal 5 of the USB interface J2, and the terminal 30 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the USB interface J3 through the current limiting resistor R52; The terminal 10 of the second microcontroller chip U5 is electrically connected to the terminal 5 of the USB conversion chip U3; The terminal 11 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the USB conversion chip U3; Terminal 12 of the second microcontroller chip U5 is electrically connected to terminal 1 of the NFC interface J5 via a current limiting resistor R86; Terminal 13 of the second microcontroller chip U5 is electrically connected to terminal 2 of the NFC interface J5 via a current limiting resistor R83.

3. The multifunctional key touch circuit according to claim 1, characterized in that: The multi-function key touch circuit also includes an identity recognition module and a current detection module. The identity recognition module includes a transient suppression diode D87 and a transient suppression diode D88. The identity recognition module also includes a resistor R129 and a resistor R132. The current detection module includes a current detection amplifier chip U7 and a current detection amplifier chip U8, wherein: The terminal 16 of the second microcontroller chip U5 is electrically connected to the terminal 1 of the current detection amplifier chip U7 through the resistor R129, and the common terminal between the resistor R129 and the terminal 1 of the current detection amplifier chip U7 is connected to the transient suppression diode D87; Terminal 17 of the second microcontroller chip U5 is electrically connected to terminal 1 of the current detection amplifier chip U8 through resistor R132, and a common terminal between the resistor R132 and terminal 1 of the current detection amplifier chip U8 is connected to a transient suppression diode D88.

4. The multifunctional key touch circuit according to claim 1, characterized in that: The multi-function key touch circuit also includes a vibration motor module, which includes a vibration motor MOTOR1 and a contact connector J7. The vibration motor module also includes a vibration motor MOTOR2 and a contact connector J6, wherein: Terminal 1 of the vibration motor MOTOR1 is electrically connected to terminal 1 of the contact connector J7, terminal 2 of the vibration motor MOTOR1 is electrically connected to terminal 4 of the contact connector J7, and the common terminal between terminal 1 of the contact connector J7 and terminal 2 of the contact connector J7 is connected to the common terminal between terminal 3 of the current detection amplifier chip U7 and terminal 4 of the current detection amplifier chip U7; Terminal 1 of the vibration motor MOTOR2 is electrically connected to terminal 1 of the contact connector J6, terminal 2 of the vibration motor MOTOR2 is electrically connected to terminal 4 of the contact connector J6, and the common terminal between terminal 1 of the contact connector J6 and terminal 2 of the contact connector J6 is connected to the common terminal between terminal 3 of the current detection amplifier chip U8 and terminal 4 of the current detection amplifier chip U8.

5. The multifunctional key touch circuit according to claim 4, characterized in that: The vibration motor module also includes an N-channel enhancement type MOSFET tube Q2 and a small signal switch diode D2. The vibration motor module also includes an N-channel enhancement type MOSFET tube Q1 and a small signal switch diode D3, wherein: The common end between terminal 1 of contact connector J7 and terminal 2 of contact connector J7 is connected to the cathode of small signal switch diode D2, the common end between terminal 3 of contact connector J7 and terminal 4 of contact connector J7 is connected to the common end between the anode of small signal switch diode D2 and the drain of N-channel enhancement type MOSFET Q2, and the gate of N-channel enhancement type MOSFET is connected to terminal 39 of the second microcontroller chip U5 through resistor R18; The common end between terminal 1 of contact connector J6 and terminal 2 of contact connector J6 is connected to the cathode of small signal switch diode D3, the common end between terminal 3 of contact connector J6 and terminal 4 of contact connector J6 is connected to the common end between the anode of small signal switch diode D3 and the drain of N-channel enhancement MOSFET Q2, and the gate of N-channel enhancement MOSFET is connected to terminal 40 of the second microcontroller chip U5 through resistor R18.

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